MALFORMATIONS OF THE BULBUS CORDIS 1 5 



stomach ; the bulbus, the pyloric part of the stomach ; the upper orifice 

 of the bulbus, the pyloric orifice. Lesser and greater curvatures are 

 distinctly marked, the lesser curvature being the result of a restricted 

 growth along one margin of the cardiac tube, which brings the upper 

 orifice of the bulbus towards and against the auriculo-ventricular orifice, 

 in the same way as an exaggeration of the contracture of the lesser 



Figure 8, heart of a fish (Echinorhinus spinosus) from a specimen in the Museum of the 

 Royal College of Surgeons, England. 



(i) Primitive aortic stem giving off branchial aortic arches. 



(2) Bulbus cordis. 



(3) Upper orifice of bulbus. 



(4) Lower orifice of bulbus. 



(5) Ventricle. 



(6) Auriculai canal. 



(7) Left auricle. 



(8) Right auricle. 



(9) Sinus venosus. 



curvature of the stomach would approximate the pyloric and oesophapeal 

 orifices. In the fourth week, the parts of the human heart correspond 

 in shape and position to those of the fish just described (see figure 7, A, 

 B), there being this difference that the lesser curvature is undergoing a rapid 



(69) 



